1. Field of the Invention
The present invention relates to a heat exchanging device adapted to be, for example, used for an oil cooler using engine cooling water for cooling different kinds of oils, for various lubrication and other operational purposes in an automobile, such as engine oil, transmission oil and power steering oil.
2. Description of Related Art
In an automobile, various kinds of oils, such as engine oil, transmission oil, and power steering oil are used. Various types of oil coolers have been used for obtaining exclusive cooling of these oils, which causes spaces occupied thereby to increase irrespective of a limited available space in an engine compartment of an automobile, on one hand, and the increased cost due to the necessity for additional parts well as additional assembling steps, on the other hand.
In order to obviate these problems, a Japanese Un-Examined Utility Model Publication No. 64-8513 discloses an oil cooler which includes a pair of cooling units arranged in a side-by-side relationship for separately cooling different kinds of oils, while an engine cooling water is commonly used as a cooling medium for both of the cooling units. Each unit has a stack of heat exchanging plates, between adjacent water passageways for a flow of cooling water and oil passageways for flows of oils are alternately created. A separation plate is arranged between the adjacent water passageways of the first and second cooling units for separating the flows of the two kinds of oils. A cooling fin is arranged in each of the oil passageways. This prior art is, however, defective in that its construction is complicated in view of a necessity of special parts, such as a partition wall for separating the water passageways between the first and second heat exchanging units.